“If you try to shoot at me, I will shoot police officers on site. I have killed before and not afraid to do again,” he said.

Former police chief and law enforcement consultant Gene Ferrara said detectives will work to track the phone call, even though it came from a blocked number.

“Whatever information comes in, that’s where law enforcement will start their investigation, trailing that back trying to find the source of it,” said Ferrara.

The group is also using social media to antagonize officers.

“Depending what information a law enforcement agency has to begin with,” Ferrara said, “they could go to court and with enough probable cause and get a subpoena, in which case, all of that information about the twitter account would be retrievable by that agency.”